They have FAQ's linked to that page. Here you go:
Q. How does a softbox attach to a light stand? Can I use the DynaPhos soft box with any of my studio lights?
A. The most common method is to attach the soft box to the light head using the connector (provided with DynaPhos light kits), the light head then mounts to your stand. However, DynaPhos connectors also have a screw hole on the bottom that allows the connector to be attached directly to the light stand. DynaPhos soft boxes are universal and can be used with most lighting systems (both tungsten and strobe) provided the correct connector is used.
I'm not sure if this will take care of a way to mount the SB800, but someone like Bogen probably makes an accessory to handle that.